Chichimec warriors fly from their mythical place of origin to join the Toltecs in a victorious battle for the city of Cholula. (Courtesy University of New Mexico Press)

Outside the village of Oxtotipan, 90 miles southeast of Mexico City, archaeologist Miguel Medina Jaen and I stand on the lip of the Barranca del Aguila, a 300-foot-deep canyon cut by a spring-fed river. The rock walls beneath us are pocked with dozens of caves that were carved into ritual chambers that may date to as early as 950 B.C.

Medina first came here on archaeological surveys in the 1990s. He has explored and documented more than 50 of the canyon's caves and found a variety of ritual constructions--wall niches, gravelike trenches in floors, windows, and shafts in ceilings to let in light and mark important days of the year. His guide throughout these projects has been a 16th-century bark-paper document called the Map of Cuauhtinchan No. 2 (MC2) that was used to reinforce the territorial claims of the Chichimecs, who settled the area 800 years ago.

After the conquest, Chichimec priests make offerings at the temple in Cholula (Courtesy University of New Mexico Press)

An illustration in the top-left corner of the map shows Chichimec warriors flying out of a seven-chambered cave following their goddess Itzpapalotl, who carries a severed human leg as a battle standard. It is a graphic representation of the Chichimec creation story. Some of the caves of the Barranca del Aguila were carved to resemble the mythical seven-chambered cave, called Chicomoztoc, establishing a link between this place and the ancient creation story.

The MC2, however, is more than a representation of the geography; it records a journey, a history, and--at its deepest level--how the Chichimecs saw their place in the world.

Opening a copy of the map, Medina shows me how the canyon and the village of Oxtotipan were depicted. There is no drawing of a village, only a collection of cryptic symbols. The canyon is represented by a string of white rocks spewing water, where Lord 13 Rain, the ruler who conquered the village in A.D. 1183, and his wife sit beside a flowering plant, a tree, and a mound with a dog's head.

Oxtotipan's prominent place on the map stood out, and it was one of the reasons Medina came here to look for archaeological sites. "The person who made the map had an image in his mind of the regional geography, the historical events, and the mythology," says Medina. "The map brings together all of those things into a single document."